Germany just switched on 124 nearly invisible turbines in the Rhine that keep generating after the sun sets and the wind dies — the one gap solar and wind never could close

I am going to leap to the conclusion that you have never been a part of commissioning a major infrastructure project

Will there be enough water for ships on the Rhine once they activate all 124 turbines?

/s

There's little use for these in summer anyway

Also, a lot cheaper because you don't need literally thousands of tons of steel reinforced concrete.

Which also cuts down on the carbon footprint of the energy generated.

Also probably not useful in a decade because Europe is drying out. We're seeing droughts hitherto unfathomable.

They'd still shred some fish, no?

Mostly less impact on important shipping routes.

Yea but doing it without a dam is pretty cool

Salt. The condiment basil and thyme never could replace.

more efficient waterwheels

....but yeah, theyre basically waterwheels.

Lets think about that.

• The rivers flow rate is the product of its cross section times the flow speed.
• The flow rate is also the sum of all the runoff and streams that end in the river above any given point.

So, if what you assume were true, the flow speed would sink. The ingress flow rate would not reduce though, why should it, so the only way to keep the ratio between flow speed and cross section, aka the flow rate constant would be to increase the cross section area. So, the water level would have to rise, no other way to achive that. So the question is: "Will the river in its entire length raise its level when we put these turbines in at any point?" - that would be a great way to get hundres kilometers of deeper shipping lanes for free, but no, of course it won't.

The mass of earth provides arbitrary acceleration potential but it is per unit of vertical drop, the roughness of the stream determines how much of that is converted into nonsense like hydropower or cool rapids that throw water in every direction.

What limits the density of turbines is a potential energy calculation frameable in terms of the minimum vertical drop between each turbine that still allows enough kinetic energy to be harnessed to make the practical engineering worth it.

Also turbulence in the immediate vicinty to the turbine is always going to increase entropy downstream making any energy extraction process less efficient past a certain density.

Finally remember that rivers are fundamentally histories of the path of least resistance as it changed over time, anything you stick into that context will have to have a preceding artificial structure to draw the whole of the river together or at least a critical mass of it in order to harness the energy otherwise if whatever you construct is too "inefficient" for the water vs. another path than the bulk of the water will take the lower energy path and make your construction irrelevant. This is a basic point but it is easy to miss if you only think with an engineer hat on and only consider the raw stats of the turbine and the raw physical energy in the river.

Ah yes, this is how innovation works. Try once and it it fails, stop there.

Totally. It's Germany and therefore everybody can install stuff in a major waterway without any regulation. The company also installed them in the middle of the river where all ships are going in order to sink them.

They probably ignored navigation when planning and then installing these. It will be a great oopsie